1. Field of the Invention
The present invention generally relates to a method for capturing an image, in particular, to a method for capturing a three dimensional (3D) image.
2. Description of Related Art
A stereo camera consists of two lenses having the same specifications, and a distance between the two lenses is about 7.7 cm, thus simulating an actual distance between a person's eyes. Parameters of the two lenses, such as focal lengths, apertures, and shutters are controlled by a processor of the stereo camera. By triggering through a shutter release, images of the same area but of different perspectives are captured and used for simulating a left-eye image and a right-eye image of a human.
The left-eye image and the right-eye image captured by the stereo camera are alternately displayed by a display device at a frequency exceeding persistence of vision of the human eyes, and meanwhile with the switching of liquid crystal shutter glasses worn on the human head, a human can view the corresponding left-eye image and the right-eye image with the left and right eyes. After being conducted to the cerebral cortex, the left-eye image and the right-eye image are fused into a single image by the cortical centre. Since the left-eye image and the right-eye image captured by the stereo camera may be slightly different in angles, a certain parallax exists between two object images formed on the retinas, and the object images of different perspectives in the two eyes can be fused by the cortical centre to make a human have a three dimensional impression.
Presently, the common method for capturing a 3D image is performed by using a stereo camera having two lenses. As long as capturing parameters are adjusted to be consistent with each other, a 3D image with a good imaging effect can be captured. However, in the structure of this type of stereo camera, two groups of lenses and sensors are required, and thus the cost is high. Another method for capturing a 3D image is to capture the image by horizontally moving a single-lens camera. However, the most significant problem in the method is the stability, that is, when the user does not accurately control the horizontal shift, the parallax is likely to become too large or too small, which will influence the imaging effect of the 3D image.